JPH02167979A - Open and shut device - Google Patents

Abstract

PURPOSE:To prevent generation of dust resulting from a contact bearing and to keep it clean, by supporting movable parts without contacting by a magnetic bearing and further by driving the movable parts with a linear motor. CONSTITUTION:An open and shut 7 fixed as a door or a slider 1 formed as a unit therewith is supported by a magnetic bearing comprising a guide rail 3 and respective two couples of electromagnets 2 fixed at least at front and rear portions of a slider 1 with an angle of about 45 degrees against the centerline of the guide rail 3. A magnetic bearing comprising electromagnet to prevent deflections to the revolution and a guide rail 9 is arranged under the open and shut member 7. It may be arranged at the upper part of the slider 1. When electric current flows through the electromagnet 2, the open and shut member floats magnetically by the attraction of the electromagnet 2 with a certain distance from the rail 3 and the open and shut member 7 can be driven along the rail 3 by a linear motor comprising a stator coil 4, fixed at the slider 1, and a magnet 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an opening/closing device, and particularly to an opening/closing device for opening and closing the door of a clean room.

[Prior Art and Problems to be Solved by the Invention] In semiconductor processes, it is necessary to prevent indoor dust contamination as much as possible in order to improve the yield of semiconductors.

For this reason, semiconductor manufacturing is performed in a clean room. Lean room doors like this are constructed with a sliding mechanism that slides laterally, but since they are supported by contact with rolling bearings, they become a source of dust.
This had the disadvantage of causing a decrease in cleanliness.

Therefore, the main object of the present invention is to provide an opening/closing device that uses a magnetic bearing and a linear motor to open and close movable parts such as doors without contact, without contaminating the inside of a clean room.

[Means for Solving the Problems] The present invention is a switching device for opening and closing a movable part,
It is configured with a magnetic bearing for supporting the movable part in a non-contact manner and a linear motor for driving the movable part.

[Function] In the opening/closing device according to the present invention, the movable part is supported by a magnetic bearing in a non-contact manner and the movable part is driven by a linear motor, so that generation of dust due to contact support can be prevented.

Embodiment of the Invention FIG. 1 is a side view of an embodiment of the invention, and FIG. 2 is a front view of the same, with main parts cut away.

First, the configuration of an embodiment of the present invention will be described with reference to FIGS. 1 and 2. The opening/closing part 7 serving as a door is attached to or integrally formed with the slider 1, and the slider 1 is supported by a magnetic bearing consisting of an electromagnet 2 and a guide rail 3. The guide rail 3 is formed in a semi-cylindrical shape.

Two sets of electromagnets 2 are fixed to the slider 1 at an angle of about 456 with respect to the central axis of the guide rail 3 made of magnetic material. Note that the electromagnets 2 are also arranged before and after the slider 1, and at least four sets are required. A sensor 10 for measuring the gap between the electromagnet 2 and the guide rail 3 is fixed to the slider 1 near each set of electromagnets 2.

The stator coil 4 and the magnet 6 attached to the fixed part 5 constitute a linear motor, and the opening/closing part 7 is driven along the guide rail 3 by this linear motor.

The lower part of the opening/closing part 7 is supported by a magnetic bearing made up of an electromagnet 8 for preventing swinging of the opening/closing part 7 in the direction of rotation, and a guide rail 9 made of a magnetic material. Further, a gap sensor 11 for detecting the gap with the guide rail 9 is provided near the electromagnet 8 at the bottom of the opening/closing section 7. Note that when no current is applied to the electromagnet 2,
A stay 12 is provided around the slider 1 to touch down the slider 1.

Next, the operation of one embodiment of the present invention will be explained. Now, when current is applied to the electromagnet 2, an attractive force is exerted between it and the guide rail 3. The attraction force is controlled to keep the gap between the electromagnet 2 and the guide rail 3 constant, and the slider 1 becomes magnetically levitated relative to the guide rail 3, and the slider 1 is attached to the guide rail 3 by a magnetic bearing. It will be supported. In this case, the suction directions of the two left and right electromagnets 2 are at the angle at which they are installed, that is, 45 degrees each with respect to the center of the guide rail 3, so in addition to the force that attracts the slider 1 upward, the horizontal direction of the slider It also has the effect of generating a force that prevents shaking.

On the other hand, when the stator coil 4 is energized, the slider 1 travels along the guide rail 3 by a linear motor consisting of a magnet 6 attached to the fixed part 5 and the stator coil 4 fixed to the slider 1. Since the opening/closing part 7 is fixed to the slider 1, the opening/closing part 7 also moves as the slider 1 moves, and this opening/closing part 7 becomes an opening/closing door.

When the switchgear in this embodiment is used in a clean room, the pressure inside the clean room is set to be slightly higher than that outside, and due to the pressure difference, the switchgear 7
A force that causes the opening/closing part 7 to rotate about the center of the guide rail 3 acts on the side surface of the opening/closing part 7 . However, in this embodiment, in order to prevent its rotation, an N pole is also provided at the bottom of the opening/closing part 7.

A pair of electromagnets 8 having an S pole, a guide rail 9 made of a magnetic material, and a gap sensor 11 are provided.The rotation of the opening/closing part 7 is controlled by controlling the electromagnet 8 based on the output of the gap sensor 11. Can be suppressed.

In the above embodiment, two sets of electromagnets 2 are provided around the guide rail 3 to provide attractive force and horizontal restraining force, but by increasing the number of these electromagnets 2, each A force in the direction may be generated.

FIG. 3 is a side view showing another embodiment of the invention. In the embodiment shown in FIGS. 1 and 2 described above, the opening/closing part 7
The electromagnet 8 for preventing rotation, the guide rail and the gap sensor 11 are provided at the lower end of the opening/closing part 7. However, in the embodiment shown in FIG. The sensor 31 is arranged on the slider 21 and two guide rails are attached to the fixed part 25. Furthermore, in the embodiment shown in FIG.
Permanent magnet 6 and stator coil 4 that make up the linear motor
is placed on the upper part of the guide rail 3, but in the embodiment shown in FIG.
2, the permanent magnet 26 and the stator coil 24 are parallel to each other.
are arranged. The opening/closing part 27 is fixed to the slider 21, and a sealing member 3 is provided at the part of the opening/closing part 27 that contacts the floor surface.
3 is installed. Electromagnet 22 in this embodiment
magnetic bearing and permanent magnet 26 and stator coil 2
The rolling prevention operation of the opening/closing section 27 consisting of the linear motor 4, the electromagnet 28, and the guide rail 29 is performed as described above.
This is the same as the embodiment shown in FIG.

As described above, according to this embodiment, the electromagnet 28, the guide rail 29, and the gap sensor 31 for preventing the rotation of the opening/closing part are arranged on the slider 21, so there is no need to provide a recess in the floor surface, and the opening/closing part is not rotated. It is possible to eliminate the fear that dust will accumulate under the portion 27.

In the above two embodiments, both linear motors using permanent magnets have been described, but other linear motors such as linear induction motors, linear pulse motors, etc. may also be used.

[Effects of the Invention] As described above, according to the present invention, a slider supported by a magnetic bearing is provided with an opening/closing section, and this is driven by a linear motor, so that a completely non-contact opening/closing device can be constructed. . Therefore, the generation of dust caused by opening and closing can be prevented, so when the present invention is used in a clean room, opening and closing operations can be performed without reducing the cleanliness.

Furthermore, due to the non-contact support, there is no mechanical noise associated with opening and closing, and the lifespan of the opening and closing parts can be extended. Note that one of the features of this switchgear is that it can be used even in a vacuum.

[Brief explanation of the drawing]

FIG. 1 is a side view of one embodiment of the present invention. FIG. 2 is a front view of one embodiment of the present invention, with main parts cut away. FIG. 3 is a side view showing another embodiment of the invention. In the figure, 1.21 is the slider, 2.8, 22.28
is an electromagnet, 3.23, 9.29 is a guide rail, 4.24
is a stator coil, 5.25 is a fixed part, 6.26 is a permanent magnet, 7, 27 is an opening/closing part, 10.30 is a sensor, 11.
31 is a gap sensor, 12, 32 is a stay, and 33 is a sealing material.

Claims (4)

[Claims] (1) An opening/closing device for opening and closing a movable part, comprising: a magnetic bearing for supporting the movable part in a non-contact manner; and a linear motor for driving the movable part. (2) A magnetic bearing for levitation is provided at the upper end of the movable part, and a magnetic bearing for steady rest is provided at the lower end.
Switching device as described in section. (3) The opening/closing device according to claim 1, wherein the movable part is provided with a magnetic bearing for levitation and a magnetic bearing for steady rest in parallel. (4) The opening/closing device according to claim 2 or 3, wherein the magnetic bearing further includes at least four sets of electromagnets arranged such that the directions of their respective attractive forces form a certain angle.